A study in the Lancet Infectious Diseases journal stated that the man was the fifth known patient of the novel coronavirus who suffered from the infection for second time, and the first such patient in the US.
The man, who was a resident of Washoe County, had to be hospitalised when he was reinfected with the disease. He had no history of underlying problems or serious diseases.
According to US media reports, the man recovered for the second time from the coronavirus but his case raises serious questions on developing protective immunity against the infection.
The number of deaths caused by the novel infection, which has had tremendous political, economic, social and health effects on countries around the globe, has reached 1.8 million.
On March 25, the medical journal said that the man experienced certain symptoms which were familiar with the coronavirus infection such as sore throat, cough, headache, nausea and diarrhea.
He presented to a community testing event held by Washoe County Health District on April 18 and tested positive for COVID-19 for the first time.
The patient’s initial symptoms fully cleared during isolation on April 27. He felt better after isolation and tested negative for the virus in May on two separate occasions.
However, a few days after he tested negative for coronavirus, the man started experiencing symptoms again from May 28 which included fever, headache, dizziness, cough, nausea, and diarrhea.
Forty-eight days after he tested positive for the infection for the first time, on June 5, the man contracted coronavirus again, with this time the symptoms being ‘severe’.
The man got admitted to a hospital for shortness of breath but after a few days, recovered and was discharged. Scientists said that the man had contracted the virus for a second time rather than his infection growing stronger.
They came to the conclusion as a comparison of the genetic codes showed “significant differences” between each variant associated with each instance of infection.
“These findings suggest that the patient was infected by SARS-CoV-2 on two separate occasions by a genetically distinct virus. Thus, previous exposure to SARS-CoV-2 might not guarantee total immunity in all cases,” the study’s authors said.
“All individuals, whether previously diagnosed with COVID-19 or not, should take identical precautions to avoid infection with SARS-CoV-2,” they added.